1. Field of the Invention
This invention relates to communication between chips in a mainframe Input/Output (I/O) subsystem, and more particularly relates to queue management of a queue of global Link Control words (LCWs) in an I/O subsystem.
2. Description of Background
In many data processing systems such as the IBM S/390 and the IBM eServer zSeries 990 server, the I/O subsystem used the Self-Timed Interface (STI) to transmit data between chips. The STI protocol allows communication between chips in the system, not only via information packets, but also via smaller global LCWs.
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U.S. Pat. No. 5,649,291 issued Jul. 15, 1997 to Tayloe for COMMUNICATION SYSTEM AND METHOD USING SUBSCRIBER UNITS TO EVALUATE HAND-OFF CANDIDATES discloses a cellular telecommunication network having earth orbiting satellites. Each satellite receives cell cluster lists that are valid for cells the satellite projects toward the earth and for predetermined periods of time.
U.S. Pat. No. 5,944,797 issued Aug. 31, 1999 to Gregg et al. for DATA MOVER HARDWARE CONTROLLED PROCESSING IN A COMMANDING SYSTEM AND IN A COMMANDED SYSTEM FOR CONTROLLING FRAME COMMUNICATIONS ON A LINK discloses an I/O system that reduces or eliminates the involvement of central processors in the message block handling of received communication-link responses within a central processing complex.
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